Curine

Bebeerine, CjjHjgOjNj. This alkaloid has been described imder various names, pelosine, chondrodendrine, chondodendrine and curine (Z-form) whose origin is described elsewhere (pp. 363 and 374). It crystallises with one molecule of benzene, m.p. 161°, or 213° (solvent-free) or from methyl alcohol, m.p. 214°, and has [ajn 298° (EtOH) for the d- or Z-form (Scholtz ). Spath et recorded m.p. 221-221-5° (vac.) for both forms and + 332° and — 328° for the d- and Z-forms, in pyridine. 

These results show that bebeerine is represented by (I Rj = R3 = H and Rj = R = Me). See also curine (Z-bebeerine), dealt with as a curare alkaloid (p. 374). 

Para, Tube or Bamboo Curare. This variety was packed in sections of bamboo, but this almost traditional information needs modification since tube curare became a commercial article. It is now a viscous, solid or even powdered extract, exported in sealed tins. In view of the relationship established between bebeerine, curine, and tubocurarhie, the active alkaloid of this variety of curare, the suggestion was made, first by Spath, Leithe and Ladeck, and more definitely by King that its botanical source should be sought among the Brazilian Menispermaceae, and as shown later the search for the source of the d-tubocurarine found in this variety of curare has been narrowed down to Chondrodendron tomentosum, or possibly a closely related species liable to be confused with it. 

Constitution. Tubocurarine chloride and curine methochloride l-bebeerine methochloride) are isomeric, and though possessing rotations of... 

These results seemed to establish with certainty that the active component of tube curare is derived from Chondrodendron tomentosum, but the matter again became doubtful when King reported that in the stems of a carefully authenticated specimen of the plant, collected at Tarapoto in Peru, he had found 1-curine and Z-tubocurarine chloride. This is the first recorded natural occurrence of the latter and seems to indicate either that the alkaloidal components of the plant are not constant in character, or that the botanical description of Chondrodendron tomentosum covers two species containing the dextro- and Icevo- quaternary alkaloids respectively. 

The process of isolation finally adopted by the former authors consists in precipitating as reineckates the water-soluble bases contained in a methyl alcoholic extract of the curare. The mixed reineckates are further purified, by solution in acetone and precipitation with water as often as may be necessary. The product so cleaned represents the bulk of the biological activity of the crude drug the mother liquors may contain curine (p. 374), which indicates a menisperm as one of the components of such curares. The mixed reineckates are then fractionated chromato-graphically over alumina and the components isolated as chlorides by the use of silver sulphate and barium chloride in succession. This process has been modified in detail by Schmid and Karrer, who have also found that with their curare, the more soluble reineckate fraction includes less potent quaternary alkaloids. 

The material first used by Wieland et al. was gourd curare from the middle Orinoco district, near Urbana, in Bolivar State, Venezuela, but in the fomth paper (1941) results are recorded for curares from Colombia and Venezuela, for which more precise details of origin are not available and there is considerable difference in the nature and quantity of the alkaloids in the various samples used. An examination has also been made of the bark of Strychnos toxifera, and one of the alkaloids (toxiferine II) it contains has been found in some of the curares examined. In all, ten alkaloids have been obtained and characterised and, with the exception of curine, they are all of quaternary type. They are named toxiferine, dihydrotoxiferine, or calabash-curarine (shortened to C-curarine in practice) according to type, and the variants within the type are distinguished by numbers, or numbers and letters, e.g., toxiferine I, toxiferine Ilb. 

Alkaloids of Curare Curine, Tubocurarine, Protocuridine, Calabash-curare I, etc., including Erythrina alkaloids Alkaloids of Ipecacuanha. ... 

Govindachari and Viswanathan identified the aristolochine which was isolated by Krishnaswamy et al. 1935 (55) as /-curine by H NMR, MS, and direct comparison with authentic sample of /-curine to establish its identity (48,49). El-Sebakhy and Waterman reported the results of an examination of the leaves of A. elegans in which a bisbenzyl isoquinoline alkaloid, (—)-(/ ,/ )-7 -0-methyl cuspidaline (35), was isolated. This study failed to show the presence of any other nitro compounds in the leaves of A. elegans (50). 

Cissampelos pareira L. Xi Sheng Teng (Ice vine) (plant) Cissampareine, hayatine, pelosine, isoquinoline, hayatinine, berberine, dl-beheerine, dl-curine, D-guereitol, d-isochondrodendrine, hayatidine, cissamine, menisnine, reserpine, cissampeline.33-450 Blockade of NMJ depolarization. Used externally on wound surfaces to relieve pain. 

The alkaloid content of curare is from 4% to 7%. The most important constituent in menispermaceous curare is the bis-benzyltetrahydroisoquinoline alkaloid (+)-tubocurarine (Figure 6.48). This is a monoquaternary ammonium salt, and is water soluble. Other main alkaloids include non-quaternary dimeric structures, e.g. isochondrodendrine and curine (bebeerine) (Figure 6.48), which appear to be derived from two molecules of (R)-N-methylcoclaurine, with the former also displaying a different coupling mode. The constituents in loganiaceous curare (from calabash curare, i.e. Strychnos toxifera) are even more complex, and a series of 12 quaternary dimeric strychnine-like alkaloids has been identified, e.g. C-toxiferine (toxiferine-1) (see page 359). 

An anomalous X-ray scattering study of (+(-tubocurarine dibromide (73 4MeOH) confirmed the structure and absolute configuration earlier assigned. The N-N distance is 10.66 A (47,48). A purified sample of (+(-tubocurarine chloride (73a), prepared by selective quatemization of (+(-tubocurine (74) (Section V,B,1), gave the anomalous MS behavior previously ascribed to thermal disproportionation or the presence of impurities. In particular, the MS has mle 594 [17%, (M - 15)+, loss of Me] but also 608 (3.7%) and 622 (0.5%). The higher peaks seem to be due to a thermal Hofmann elimination followed by recombination with methyl radicals. Similar behavior is observed with the tertiary bases (—)-curine (75) and (+(-tubocurine (74), and may be general for alkaloids of this skeletal type (49). 

Guatteria megalophylla Diels (Annonaceae) afforded (/ ,/ )- , 0-dimethylcur-ine (144), C38H42N206, mp 133-136°C (EtOAc-cyclohexane), identified by UV, NMR, MS, and ORD, and by comparison with a sample synthesized by CH2N2 methylation of (/ ,/ )-l2 -0-methyIcurme (145, Section II,C,64), also isolated from this plant (82). (/ ,/ )-< ,0,-Dimethylcurine had been prepared by methylation of (/ ,/ )-curine (75) (83), but was not previously reported in nature however, (5,S)-0,0-dimethylcurine is a known alkaloid of Cissampelos pareira (84). 

TLC separation and densitometric determinations of alkaloids of Cyclea densi-flora, Stephania herbacea, S. brachandra, and S. tetrandra have been described the bis bases isolated were isochondodendrine, curine, berbamine, cycleanine, cepharanthine, curarine, fangchinoline, homoaromoline, isotetrandrine (= iso-sinomenine A), and tetrandrine (= sinomenine A) (330a). A TLC-densitometric method for assay of dauricine from biological specimens has been reported (331). Tubocurarine served as a test case for pseudophase liquid chromatogra-... 

Curine d-Chond(r)odendrine, rf-bebeerine, aristolochine fC36 alkaloid) 436-05-5 X... 

Hayatinine O-Methylbebeerine, 0-4 -methyl-curine, O-methylchondroden-drine 6879-67-0 b... 

Cleistopholis staudtii Chondrofoline, curine, cycleanine, isochondodendrine 541... 

Recently the leaves of another species, Cyclea atjehensis Forman, have been investigated by Shamma s group (22). It was found that the alkaloids of C. atjehensis are head-to-tail bisbenzylisoquinoline alkaloids of the curine type. Four new and novel amidic bisbenzylisoquinolines... 

Dc Angclis, M., Curin, A.C., McSweeney, P.L., Faccia, M., Gobbetti, M. 2002. Lactobacillus reuteri DSM 20016 Purification and characterization of a cystathionine gamma-lyase and use as adjunct starter in cheesemaking. J Dairy Res 69 255-267. 

The bisbenzylisoquinolines have been the subject of many pharmacological studies, motivated originally by the knowledge that quaternary alkaloids of this type are the active constituents of tube curare. Certain nonquaternary bisbenzylisoquinolines, notably belonging to the curine group, are also smooth muscle re-laxants many bisbenzylisoquinolines are hypotensive, and a few possess anti-... 

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